1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2002 Society of Automotive Engineers, Inc.All rights reserved. No part of this
3、 publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying,recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (o
4、utside USA)Fax: 724-776-0790Email: custsvcsae.orgSAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001STANDARDJ2540ISSUEDJUL2002Issued 2002-07Messages for Handling Strings and Look-Up Tables in ATIS StandardsForewordThis SAE Standard outlines the methodolo
5、gy and messages used to convey textual strings ofmessages to consumers in ATIS and other areas. It outlines how concepts originally developed for SAE J2369 canbe expanded to cover the various types of ITIS messages used in US deployments in a consistent way and meet anumber of goals. Among these goa
6、ls is overcoming the historical problems of obsolete tables without requiring themutual agreement and updating of all deployed users. It provides implementation details for deployments wishingto use tables in ways ranging from non-changing (“static”) embodiments, to highly flexible and changing tabl
7、estructures (“dynamic”), and provides a single uniform formatting standard for all (regardless of specific content). Inthe related documents are encodings of selected national level tables used in various deployments. See also: SAE J2540-1 RDS Phrase Lists SAE J2540-2 ITIS Phrase Lists SAE J2540-3 N
8、ational Names Phrase Lists TABLE OF CONTENTS1. Scope . 32. References . 32.1 Applicable Publications 32.2 Related Publications . 43. Definitions. 44. Overview 84.1 Goals of the Document. 84.2 Limits of This Approach 104.3 Summary 135. Operating Concepts . 145.1 Assignment of a Table in Use. 145.2 Pr
9、operties of a Table 145.3 Nesting of Tables . 145.4 Supported Vocabularies and Alphabets . 15SAE J2540 Issued JUL2002-2-5.5 Table Expansion Values . 165.6 Simple Text within Strings 175.7 Registering a table within ITS . 185.8 Adding to a tables entries 185.9 Table Resorting 185.10 Considerations fo
10、r end user equipment 195.11 Changes to existing standards . 196. Messages .196.1 The Table Message 206.2 The Partial Table Message.226.3 The Table Request Message 236.4 The Index Translate Message 236.5 The Index Translate Request Message 236.6 The String Translate Message 246.7 The String Translate
11、 Request Message . 247. Data Elements 247.1 Date Element: Table-Registration-Value 247.2 Date Element: Local-Table-Flags .267.3 Date Element: About-Flags .267.4 Date Element: Index-Start 277.5 Date Element: Index-Stop. 277.6 Date Element: Index-Count 287.7 Date Element: Index-8 287.8 Date Element: I
12、ndex-11 287.9 Date Element: Index-12 287.10 Date Element: Index-16 287.11 Date Element: Table-Entry .297.12 Date Element: Local-Number . 297.13 Date Element: Included-Table-Flags 307.14 Date Element: Request-Type . 327.15 Date Element: Revision 337.16 Date Element: Word-Count .337.17 Date Element: E
13、ntry-Type 337.18 Date Element: CRC-16. 347.19 Date Element: SAE-String 348 Using This Document in Other Messages 358.1 General Comments for Use 358.2 Connecting Strings across Multiple Message Fields 368.3 Examples of use in SAE J2354 368.4 Examples of use in SAE J2369 37Table 1 Typical Multi-Part P
14、hrase Table 11Table 2 Latin_1 Character Excluded By Current SAE J2369 Codings 13Table 3 Types of Tables and Their Exception Tokens 16Table 4 Example of Table Control Expansion Bits (From SAE J2369 Table 8). 16Table 5 Example of Numeric Table Control Expansion Bits (From SAE J2369 Table 9) 17Table 6
15、Table Registration Value Ranges .25Table 7 Reserved Table Registration Values 25Table 8 Assigned Local Table Numbers 29Table 9 Reserved Table Numbering Assignments 30Table 10 Incident Flow Context Table Entries (From Table 24 of SAE J2369) . 37SAE J2540 Issued JUL2002-3-1. ScopeThis SAE Standard def
16、ines methods and messages to efficiently translate sequences of text andother types of data into and out of indexed values and look-up tables for effective transmission.This document defines:a. Methods and Data Elements for handling indexes and strings in ATIS applications and message setsb. Message
17、 Sets to support the delivery and translations of tables used in such stringsc. Tables of Nationally standardized strings for use in ATIS message descriptionsAnd examples of each in illustrative portions. While developed for ATIS use, the methods defined in this document are useful for any textual s
18、trings in anyTelematics applications found both in Intelligent Vehicles and elsewhere. 2. References2.1 Applicable PublicationsThe following publications form a part of this specification to the extent specifiedherein. Unless otherwise indicated, the latest version of SAE publications shall apply.2.
19、1.1 SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J2313On-Board Land Vehicle Mayday Reporting Interface, May 2000SAE J2353Data Dictionary for Advanced Traveler Information Systems (ATIS), October 1999SAE J2354Message Sets for Advanced Traveler Information
20、Systems (ATIS), October 2000SAEJ2369Standards for ATIS Message Sets Delivered Over Reduced Bandwidth Media, November2000SAEJ2374Information Report based on Location Reference Message Specification, Rev. B (MDI),May22, 1997SAE J2540-1RDS Phrase ListsSAE J2540-2ITIS Phrase ListsSAE J2540-3National Nam
21、es Phrase Lists2.1.2 ANSI PUBLICATIONAvailable from ANSI, 25 West 43rd Street, New York, NY 10036-8002.ANSI X3.4American National Standard Code for Information Interchange2.1.3 CEN PUBLICATIONSAvailable from CEN, 36 rue de Stassart, B-1050 Brussels, Belgium.Traffic and Traveller1 Information (TTI) T
22、TI Messages via Traffic Message Coding- Part I: Codingprotocol for Radio Data Systems Traffic Message Channel (RDS-TMS) using ALERT-C, ISO/DIS14819-1, August 1999Traffic and Traveller Information (TTI) TTI Messages via Traffic Message Coding- Part 2: Event andInformation codes for Traffic Message Ch
23、annel (TMC), PrENV 12313-2, Version 1.0, June 19962.1.4 GATS PUBLICATIONSAvailable from the GATS forum or from CEN TC278.GATS Message Set; Main Part Main 2034.pdf 05.08.99GATS Message Set; Annex 2 - Basic Information Elements A2_2033.pdf 05.08.992.1.5 ISO P UBLICATIONAvailable from ANSI, 25 West 43r
24、d Street, New York, NY 10036-8002.ISO prEN 14819-1 (1999)1. European spelling of TravelerSAE J2540 Issued JUL2002-4-2.2 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.2.1 SAE PUBLICATIONSAvailable from SAE, 400
25、Commonwealth drive, Warrendale, PA 15096-0001.SAE J2353Data Dictionary for Advanced Traveler Information Systems (ATIS), October 1999SAEJ2374Information Report based on Location Reference Message Specification, Rev. B (MDI), May22, 19972.2.2 FHWA PUBLICATIONSAvailable from Lee Simmons, FHWA, HVH-1 R
26、oom 3400, 400 7th Street SW,Washington, D.C. 20590.National ITS Architecture, Federal Highway Administration, U.S. Department of Transportation, Version2.0, September 19982.2.3 ITE PUBLICATIONSAvailable from ITE, 525 School Street SW, Suite 410, Washington, DC 20024.Message Sets for External Traffic
27、 Management Center Communication (MS/ETMC2), TM 2.01, Rev. 2.0,February 1, 20012.2.4 W3C PUBLICATIONSAvailable from W3C, http:/www.w3.org.“Hypertext Transfer Protocol - HTTP/1.1,” W3C - June 1999, RFC 2616, available at http:/www.w3.org/Protocols/rfc2616/rfc2616.txt “HTML 4.0 Specification,” W3C - D
28、ecember 1997, revised 24 April 1998 available at http:/www.w3.org/TR/1998/REC-html40-19980424 HTML 4.0 Guidelines for Mobile Access W3C Note - 15 March 1999 available at http:/www.w3.org/TR/NOTE-html40-mobile Character Model for the World Wide Web, World Wide Web Consortium Working Draft 29-November
29、-1999available at http:/www.w3.org/TR/1999/WD-charmod-19991129/.3. DefinitionsThe following terms and concepts are used in the body of this document.3.1 Alert-CA traffic message system using phrase - index encodings operating over RDS and established in1990, see ISO prEN 14819-1 (1999) for current i
30、nformation. Along with a more advanced system called Alert-Plus (and typically a pay for service system) this system has been deployed in selected major cites in Europe.Typically under local government sponsorship. A number of early US deployments by Enterprise States haveused derivative versions of
31、 the phrases established in this work for trial US deployments. A number ofcommercial vendors support derivative forms of it, both on RDS and on other media as well.3.2 CompressionThe process of replacing a sequence of simple text elements (or other strings) with a smallindex value for transmission
32、is considered to be compression in this document.3.3 Dense TableA table where the index values increase by one each time without a break in the ordering. Theindex value can be implicitly computed and therefore need not be sent. Dense tables are preferred, and areeasier to automatically generate than
33、 sparse tables.3.4 Dynamic TableA table which changes its contents periodically as a function of the textual information whichis being transmitted and which attempts to reflect to achieve the best compression in the media. As contrastedwith static tables which only change periodically. Strategies af
34、fecting the frequency of updating vary withimplementation, media, and ISP operators choices. Dynamic tables convey their changes over the samemedia as the messages using them. This is an essential aspect of their operation. SAE J2540 Issued JUL2002-5-3.5 End Using DeviceA term used in this document
35、to refer to the device which received the message andstrings that are a subject of this document. The capabilities of such a device may vary widely from one user toanother. The device is presumed to be mobile, but need not be. The end using device gets its data from theissuing ISP over the host medi
36、a. 3.6 ExceptionA token which causes some change in the flow of control in processing the stream. In thisdocument, exception tokens precede an index value and are used to select which table (and how) to expandfrom.3.7 ExpansionThe process of replacing an index value found in a string with the corres
37、ponding string or textvalue which it represents.3.8 Expansion CodeThe code which precedes an index value (also called an exception token). This codeselects which of up to four tables is to be used in expanding the string back into text and provides some controlflags for how the expansion is to occur
38、.3.9 Extending a TableThe act of adding additional index entries to the end of an existing table. All tables canbe extended. By this means new entries are added as needed while preserving the older index values.Periodically a resort may occur which reassigns the mapping of index values. The revision
39、 bits allow the enduser to determine if a table has been extended and/or resorted.3.10 FlagsOne or more bit values contained in some part of a message which effect the way a string is processedin converting it back into text. In the table message there are flags dealing with how the table itself, an
40、d howany included tables, are to be handled.3.11 Flat TableA table whose entries do not contain indexes to any other tables, i.e., a table which is entirely selfcontained. A flat table may contain nested table entries to itself.3.12 GATSGlobal Automotive Telematics Standard. A mobile phone system ba
41、sed on the GSM (Global Systemfor Mobile Communication) phone system deployed in Germany and other areas of Europe. The GATSsystems provides a message set which offers many of the same services in US ITS-ATIS. GATS is beingadvanced by the CEN TC278 process as a standard.3.13 Group 8AThe original mess
42、age type used in RDS to carry TMC messages in a complete 37-bil message.Now such messages can be carried in any valid spare group by means of a soft assignment process calledODA.3.14 Host Medium The host media are the transmission media that was used to transport the ATIS messagescontaining the stri
43、ng from the ISP to the end-using device (e.g., wireless data links, SubCarriers, digitalphones, etc.). Often such media have a limited amount of bandwidth and it is for this reason that the stringhandling methods of this document were developed.3.15 Included Table FlagsFlags providing information ab
44、out tables used in the entries of this table, found in thetable header.3.16 ISPInformation Service Provider. In the context of this document the issuing source of data formatted intoATIS messages containing strings handled in accordance with this document. No presumption is made in thisdocument rega
45、rding the business model or ownership of the ISP. The term ISP (as opposed to TMC) is oftenused to imply a private “for profit” venture. No such term is implied here.3.17 ITISInternational Traveler Information System A term coined to indicate the area of common phrases fordescribing incident events.
46、SAE J2540 Issued JUL2002-6-3.18 Local ReplacementA term for a table entry which “overlaps” another entry in another table with the sameindex value. This allow the creation of local tables which can redefine a previous entry. See also “overlapping”and 5.3 of the text. 3.19 Local Table FlagsFlags prov
47、iding information about the tables found in the table header.3.20 Local Table NumberA value assigned to any table used by the ISP in its messages. Used to relate specificstrings to this table (and any underlying tables).3.21 LRMSLocation Referencing Message Set A body of work outlining a number of “
48、profiles” used in thedescription of affected areas, typically roadway segments. The preferred methodology for use in ATIS is theISP Vehicle profile (SAE J1746) which provides a means to send Lat-Long values between the ISP and thevehicle. A highly compressed form of this is the GRID profile which is
49、 suitable for limited bandwidthapplications. Indexing values, which typically require prior agreement between users, are called Geometryprofiles in this body of work. The LMRS is expected to become an SAE Standard in the future and will reflectall the profiles then used, including indexes.3.22 Modified ASCIIThis is a derivative of the ASCII character set specified in detail in SAE J2369. It uses theupper encoding values (beyond 127) to replace the most commonly occurring double letter pairs with a singlevalue, effectiv
